A standard luggage latch has a latch element typically constituted as a hook tongue mounted on the edge of one part of the piece of luggage, typically the lid, and another part having a housing mounted on the other luggage part and incorporating a keeper mechanism that can receive and retain the tongue. An operating element on the housing is typically movable from a normal retaining position in which a latch dog engages the tongue and prevents it from being pulled out of the housing and a release position in which it permits free exit of the tongue from the housing. In addition a key- or combination-actuated mechanism is provided which can prevent displacement of the operating element into the release position to lock the latch in the latched position.
The main problem with such a system is that in the unlocked position it is possible for something to strike the operating element and pop the latch open, allowing the piece of luggage to spill open. This can happen while the piece of luggage is being handled normally and can represent a substantial inconvenience.